//
// Created by YANHAI on 2019/5/21.
//

#include <stdio.h>
#include <string.h>

int main()
{
    char str1[20] = "123";
    char str2[20] = "123";

    char *src = "hello world";
    printf("%s\n", strcat(str1, src));
    printf("%s\n", strncat(str2, src, 5));
    return 0;
}
